Surgical cutting instrument with distal suction passage forming member

ABSTRACT

A surgical instrument having a first cutting blade and a second cutting blade that rotates within the first cutting blade during a cutting operation to cause cutting windows of the cutting blades to remove tissue from a patient also includes a suction passage forming member disposed over a suction aperture of the first cutting blade. The suction passage forming member includes an inlet, an outlet and a passage between the inlet and the outlet, the outlet communicating with the suction aperture, and the inlet facing distally. The surgical instrument can be used as a suction tool by applying a vacuum through an internal bore of the second cutting blade while the second cutting blade is stopped from rotating with the cutting windows of the first and second cutting blades misaligned with each other so that the vacuum is applied through the suction aperture and the suction passage forming member.

BACKGROUND

This disclosure relates to surgical instruments, and in particular tosurgical cutting instruments that use suction, for example, poweredshavers, microdebriders and dissector blades.

Surgical apparatus used to shave, cut, resect, abrade and/or removetissue, bone and/or other bodily materials are known. Such surgicalapparatus can include a cutting surface, such as a rotating bladedisposed on an elongated inner tube that is rotated within an elongatedouter tube having a cutting window. The inner and outer tubes togetherform a surgical cutting instrument or unit. In general, the elongatedouter tube includes a distal end defining an opening or cutting windowdisposed at a side of the distal end of the outer tube. The cuttingwindow of the outer tube exposes the cutting surface of the inner tube(located at a side of the distal end of the inner tube) to tissue, boneand/or any other bodily materials to be removed. A powered handpiece isused to rotate the inner tube with respect to the outer tube while anouter tube hub (connected to the proximal end of the outer tube) isfixed to the handpiece and an inner tube hub (connected to the proximalend of the inner tube) is loosely held in place by the poweredhandpiece.

In some instruments the inner tube is hollow and has a cutting window ona side surface of its distal end such that tissue, bone, etc. will becut or shaved as the cutting window of the inner tube aligns with andthen becomes misaligned with the cutting window of the outer tube as theinner tube is rotated within the outer tube. In this regard, it can besaid that the cutting device nibbles or takes away small pieces of thebone, tissue, etc. as the inner tube is rotated within the outer tube.

In some instruments a vacuum is applied through the inner tube such thatthe bodily material that is to be cut, shaved, etc. is drawn into thewindows of the inner and outer tubes when those windows become aligned,thereby facilitating the cutting, shaving, etc. of the tissue, whichthen travels through the inner tube due to the suction. It also iscommon to supply an irrigation fluid, which can include a liquid, to thesurgical site via a passage provided between the inner and outer tubes.

SUMMARY

Many times during surgery, the surgeon wishes to apply suction to thesurgical site without performing cutting with the surgical instrument.This usually is done by withdrawing the surgical instrument andinserting a dedicated suction device (for example, a suction wand whichis a tube to which suction is applied). However, exchanging the surgicaltool for the dedicated suction device is time-consuming. Furthermore,insertion and removal of instruments into the patient can cause traumaand irritation to the passage of the patient, and thus it is desirableto minimize the number of times that surgical instruments need to bewithdrawn and inserted/reinserted into the patient.

It is conceivable that the surgeon can use the surgical cuttinginstrument as a suction device, for example, by stopping rotation of theinner cutting tube while continuing to apply suction through the innertube. By careful operation of the pedal (or other control device) whichcontrols the rotation of the inner tube, the surgeon can cause thecutting windows of the inner and outer tubes to be aligned with eachother such that suction can be applied to the surgical site through thealigned windows of the inner and outer tubes. However, because thewindows of the inner and outer tubes are cutting surfaces (and typicallyinclude serrations), most surgeons choose not to use the surgicalcutting tool as a suctioning device because tissue adjacent to the outertube window tends to be drawn into the window and partially cut and/orirritated by the cutting surfaces of the inner and outer tubes.Additionally, because the cutting windows of the inner and outer tubesare disposed on a side surface of the distal tips of the inner and outertubes, the suction is applied from the side of the distal end of thetube, which is not optimal. Most suction wands apply the suction fromthe very end of the tip such that suction is applied at the very tip ofthe suction wand.

According to an aspect of the invention, a surgical instrument thatperforms cutting also can function as a suction wand. This is achievedby providing a surgical instrument having a first cutting blade and asecond cutting blade that rotates within the first cutting blade duringa cutting operation to cause cutting windows of the cutting blades toremove tissue from a patient, and by including a suction aperturedisposed at a side of the first cutting blade near the distal end of thefirst cutting blade and opposite to the side containing the cuttingwindow, and by providing a suction passage forming member disposed overthe suction aperture of the first cutting blade. The suction passageforming member includes an inlet, an outlet and a passage between theinlet and the outlet, the outlet communicating with the suction passage,and the inlet facing distally. The surgical instrument can be used as asuction tool by applying a vacuum through an internal bore of the secondcutting blade while the second cutting blade is stopped from rotatingsuch that the cutting windows of the first and second cutting blades aremisaligned with each other and so that the vacuum is applied through thesuction aperture and the suction passage forming member.

In accordance with some embodiments, the suction aperture provided inthe first cutting blade is an elongated slot. The elongated slot issubstantially smaller than the cutting window of the first cuttingblade. When the surgical instrument is used for cutting, most of thesuction is applied through the cutting windows because the cuttingwindows are substantially larger than the suction aperture. In addition,when the cutting windows are aligned with each other (such that tissueto be cut will be drawn into the windows), the suction aperture isblocked by the second (inner) cutting blade.

The suction passage forming member has a distal end at which the inletof the suction passage forming member is located. According to someembodiments, the distal end of the suction passage forming member istapered to ease insertion of the surgical instrument into a passage of apatient. This compensates for the increase in diameter of the surgicalinstrument that is caused by the suction passage forming member.

In accordance with some embodiments, the suction passage forming memberis a half tube that is attached to an outer surface of the first cuttingblade so as to cover the suction aperture. The half tube includes aclosed end and an open end, the open end defining the inlet of thesuction passage forming member. The open end preferably is tapered toease insertion of the surgical instrument into a passage of a patient.Preferably, the half tube is made from the same material used to makethe first cutting blade. For example, if the first cutting blade ismetallic, then preferably the half tube also is metallic, and can bewelded to the first cutting blade during manufacture of the surgicalinstrument.

According to another embodiment, the suction passage forming member is atube that fits over the distal end of the first cutting blade. The tubeincludes a radially protruding portion in which the passage of thesuction passage forming member is disposed. The part of the tube formingthe inlet of the suction passage forming member preferably is tapered toease insertion of the surgical instrument into the patient passage. Thetube can be metallic or plastic, and preferably is slidably detachableand attachable to the first cutting blade.

In accordance with preferred embodiments, the surgical instrument alsoincludes a passage between the first and second cutting blades throughwhich a liquid can be supplied.

A surgical method that uses the surgical instrument includes a step ofinserting the surgical instrument into a passage of a patient, and thenperforming a suctioning operation. The suctioning operation includespositioning the second cutting blade relative to the first cutting bladeso that the cutting windows of the first and second cutting blades aremisaligned with each other so that the internal bore of the secondcutting blade does not communicate with the passage of the patientthrough either of the cutting windows of the first and second cuttingblades. While positioning the windows of the cutting blade as describedabove, a vacuum is applied through the internal bore of the secondcutting blade to draw material from the passage of the patient into theinternal bore of the second cutting blade through the suction passageforming member and the suction aperture. During the suction operation,the first and second cutting blades are not rotated relative to eachother.

The second cutting blade can be positioned relative to the first cuttingblade so that the cutting windows of the first and second cutting bladesare misaligned with each other by the surgeon operating the controls ofthe surgical instrument (for example, by operating a foot pedal) whileobserving the distal tip of the cutting instrument (for example, with anendoscope as is typically used to observe the surgical procedure) untilthe cutting window of the inner, second cutting blade is misaligned withthe cutting window of the outer, first cutting blade such that the backside of the second cutting blade opposite to the window substantiallyblocks the window of the first cutting blade.

Furthermore, a cutting operation can be performed either before, after,or both before and after, performing the suction operation. The cuttingoperation includes rotating the second cutting blade relative to thefirst cutting blade while applying the vacuum through the internal boreof the second cutting blade. Furthermore, a liquid can be suppliedthrough a passage that exists between the first and second cuttingblades during the cutting operation.

Whether the suctioning operation is performed before, after, or bothbefore and after a cutting operation, it is unnecessary to withdraw thecutting instrument when switching between a cutting operation and asuctioning operation. Furthermore, a separate suction wand may not beneeded.

BRIEF DESCRIPTION OF THE DRAWINGS

Various exemplary embodiments of the disclosed surgical tool will bedescribed in detail with reference to the following drawings in which:

FIG. 1 illustrates a perspective view of a powered surgical tool systemthat incorporates a surgical instrument, control unit, fluid source andsuction source;

FIG. 2 is a perspective view of an exemplary embodiment of a surgicalinstrument in accordance with the present disclosure;

FIG. 3 is an exploded, perspective view of a distal tip of a surgicalinstrument in accordance with a first embodiment showing the suctionpassage forming member of one embodiment separated from the outercutting blade;

FIG. 4 is a side, cross-sectional view of the FIG. 3 embodiment showingthe cutting windows of the inner and outer cutting blades in completealignment as occurs during a cutting operation;

FIG. 5 is a side, cross-sectional view similar to FIG. 4, but with thecutting windows being in complete mis-alignment so that the surgicalinstrument can used as a suction device;

FIG. 6 is a perspective view of a distal tip of a surgical instrument inaccordance with a second embodiment;

FIG. 7 is a side, cross-sectional view of the second embodiment showingthe cutting windows being in complete alignment as occurs during acutting operation; and

FIG. 8 is a side, cross-sectional view similar to FIG. 7, but with thecutting windows being in complete mis-alignment so that the surgicalinstrument can be used as a suction device.

DETAILED DESCRIPTION OF EMBODIMENTS

The following exemplary embodiments are described below with referenceto the figures in the context of human surgery, such as ear, nose andthroat surgery, and in particular sinus surgery as well as head and necksurgery. The following exemplary embodiments may also be utilized inspinal surgery, orthopedic surgery, and various other surgicalapplications. All exemplary embodiments of the invention are intended tobe used in any applicable field of endeavor.

FIG. 1 is a schematic of a powered surgical tool system. Except for thetip of the cutting tool, to be described hereafter, the system may be inaccordance with the system described in U.S. Pat. No. 7,247,161, thedisclosure of which is incorporated herein by reference in its entirety.Another system to which the invention is applicable is described in U.S.Pat. No. 7,318,831, the disclosure of which is incorporated herein byreference in its entirety. As shown in FIG. 1, the powered surgical toolsystem 1 includes a handle 2, a footswitch 4 (with pedal 12), fluid(liquid and/or gas) source 22, suction source 28, a control unit 6,fluid pump 5 and a fluid inlet/irrigation outlet 7. The system issupplied with power from a power source 16 such as a wall outlet. Thesuction source 28 may be an external suction source such as provided byattachment to a facility suction outlet mounted on a wall. The handle 2is connected, at its distal end, to a surgical instrument 8. Thesurgical instrument 8 in this embodiment includes a cutting tip at itsdistal end 8A that is used, for example, to cut, shave, remove, resectand/or abrade tissue, bone and/or other bodily materials.

FIG. 2 illustrates a perspective view of an exemplary embodiment of thesurgical instrument 8 in accordance with aspects of the invention. Theinstrument 8 incorporates an inner tube 9 and an outer tube 10. In thisexemplary embodiment, an inner tube hub 13 is formed on the second end14 of the inner tube 9 and an outer tube hub 15 is formed on the secondend 17 of the outer tube 10. The inner tube 9 is inserted into a fluidpassage 20 formed within the outer tube 10 so that the inner tube 9 isco-axially disposed within the outer tube 10 until the external distaltip of inner tube 9 contacts the internal distal surface of the outertube 10. The outer tube 10 has a larger diameter than the inner tube 9,thus allowing for insertion of the inner tube 9 within the outer tube10. However, it should be appreciated that the inner and outer tubeswill be pre-assembled prior to delivery to the customer. Thus, acustomer will most likely not be inserting the inner tube into the outertube.

The inner and outer tube hubs 13, 15 couple the inner and outer tubes 9,10, respectively, to the handle 2. Once coupled to the handle 2, theouter tube 10 will be fixed relative to the handle 2, but the inner tube9 will be rotatable relative to the outer tube 10 and the handle 2.

FIG. 3 is a perspective view of the distal tip 8A of the surgicalinstrument 8 according to a first embodiment. As shown in FIG. 3, asuction aperture 40 is provided near the distal end of the outer tube10. The suction aperture 40 is provided on a side of the distal end ofthe outer tube 10 opposite to a side containing the cutting window ofthe outer tube 10 (the cutting window is not shown in FIG. 3). In theFIG. 3 embodiment, the suction passage forming member is a half tube 50.The half tube 50 includes an inlet 52 through which the suction will beapplied to the patient passage during a suctioning operation to bedescribed in more detail below.

FIGS. 4 and 5 are side, cross-sectional views of the FIG. 3 embodiment.FIG. 4 shows the positions of the inner tube 9 and the outer tube 10when the cutting windows of those tubes are in alignment (as occursduring a cutting operation as the inner tube 9 is rotated within theouter tube 10). FIG. 5 shows the positions of the inner tube 9 and theouter tube 10 when the cutting windows of those tubes are inmisalignment (as occurs during a suctioning operation).

The outer tube 10 includes a cutting window 60 disposed at a side of itsdistal end. Thus, the outer tube 10 also can be referred to as a firstcutting blade. The inner tube 9 also includes a cutting window 30disposed at a side of its distal end. Thus, the inner tube 9 also can bereferred to as a second cutting blade. The edges of the cutting windows30 and 60 can be serrated, smooth or a combination of serrated andsmooth to form cutting surfaces. As mentioned previously, the innercutting blade 9 rotates within the outer cutting blade 10, and thus asthe inner cutting blade 9 rotates, the cutting windows 30 and 60 becomealigned with each other as shown in FIG. 4 and then become misalignedwith each other as shown in FIG. 5. When the cutting windows 30 and 60are misaligned with each other as shown in FIG. 5, the side of the innertube 9 distal tip opposite from the cutting window 30 blocks the cuttingwindow 60 of the outer cutting blade 10, as will be described in moredetail below.

The first, or outer cutting blade 10 thus is a tubular body having aproximal end and a distal end, with the cutting window 60 disposed at aside of the first cutting blade 10 near the distal end.

The inner, second cutting blade 9 is a tubular body having a proximalend and a distal end, with the cutting window 30 disposed at a side ofits distal end. As mentioned previously, the second, inner cutting blade9 is rotatably disposed inside of the first, outer cutting blade 10 suchthat the surgical instrument 8 cuts tissue by rotating the second, innercutting blade 9 within the first, outer cutting blade 10 while a vacuumis applied through an internal bore 25 of the cutting blade 9 to drawthe tissue into the cutting windows 30 and 60 of the cutting blades 9and 10 and sever the tissue by rotation of the cutting blade 9.

The first, outer cutting blade 10 includes a suction aperture 40, shownin FIGS. 3-5, at a side of its distal end opposite to the side in whichthe cutting window 60 is formed. In a preferred embodiment, the suctionaperture 40 is an elongated slot having rounded ends. When the innercutting blade 9 is stopped while in the position shown in FIG. 5 suchthat the cutting windows 30 and 60 are misaligned, suction appliedthrough the internal bore 25 of the inner cutting blade 9 will beapplied through the suction aperture 40 of the outer cutting blade 10.However, because the suction aperture 40 is disposed at a side of thedistal end of the outer cutting blade 10, such suction is not optimal ifthe suction passage forming member (the half tube 50 of the embodimentof FIGS. 3-5) is not provided. In particular, without the suctionpassage forming member, tissue tends to be drawn into the suctionaperture 40 and could be severed or at least irritated by the opening40. In addition, if suction passage forming member is not provided,tissue would tend to be sucked into the suction aperture 40 during acutting operation and thus become severed as the inner cutting blade 9is rotated. Furthermore, the suction that is applied through suctionaperture 40 is not directed towards the distal tip of the surgicalinstrument 8, but instead is directed toward a side at the distal end ofthe surgical instrument 8.

Accordingly, a suction passage forming member is disposed over thesuction aperture 40 of the outer cutting blade 10. The suction passageforming member includes an inlet, an outlet and a passage between theinlet and the outlet. The outlet communicates with the suction aperture40, whereas the inlet faces distally.

In the embodiment of FIGS. 3-5, the suction passage forming member is ahalf tube 50. The half tube 50 is attached to the outer surface of theouter cutting blade 10 over the suction aperture 40. The half tube 50includes an inlet 52, an internal passage 54 and an outlet 56 thatcommunicates with the suction aperture 40. Accordingly, and as shown inFIG. 5, the surgical instrument 8 can be used as a suction tool byapplying the vacuum through the internal bore 25 of the cutting blade 9while the cutting blade 9 is stopped from rotating and the cuttingwindows 30 and 60 of the cutting blades 9 and 10 are misaligned witheach other as shown in FIG. 5. When in the FIG. 5 position, the vacuumapplied through the internal bore 25 is applied through a suctionpassage defined by the suction aperture 40, the outlet 56, the internalpassage 54 and the inlet 52 of the half tube 50.

The surgeon operating the instrument 8 can cause the windows 30 and 60to become oriented in the misaligned state shown in FIG. 5 by, forexample, tapping on the pedal 12 that controls the instrument to causeincremental rotation of the inner cutting blade 9 while observing thedistal tip of the instrument, for example, by an endoscope, whichusually also is disposed at the operating site, until the windows 30 and60 obtain the state shown in FIG. 5. While the windows 30 and 60 aremisaligned as shown in FIG. 5, vacuum can be applied through theinternal bore 25 of the cutting blade 9 so that the surgical instrumentcan be used like a suction wand. The flow of the fluid toward thesuction passage defined by the suction aperture 40 and the half tube 50is illustrated by arrow S in FIG. 5, whereas the flow that occurs duringa cutting operation is illustrated by arrows F in FIG. 4.

Although it is not necessary, irrigation fluid also could be suppliedthrough bore 20 when in the state shown in FIG. 5.

When the surgical instrument is used for cutting (that is, when theinner cutting blade 9 is being rotated within the outer cutting blade 10while irrigation liquid and suction are applied), most of the suction isapplied through the cutting windows 30 and 60 because they are muchlarger than the suction aperture 40 and because the portion of the innercutting blade 9 distal end other than the cutting window 30 blocks thesuction aperture 40 for much of the rotation.

As noted above, the half tube 50 prevents the suction aperture 40 fromfunctioning like a cutting window by preventing tissue from enteringinto the suction aperture 40.

The half tube 50 can be attached to the outer cutting blade 10 duringthe manufacturing process of the outer cutting blade 10. For example,when the outer cutting blade 10 is made from a metal material, the halftube 50 also can be made from the same metal material and welded to thecutting blade 10.

The cutting blades 9 and 10 are made from a sterilizable material.According to some embodiments, the sterilizable material is a metal suchas stainless steel.

FIGS. 6-8 show a second embodiment. The second embodiment provides asuction passage forming member in the form of a tube 80 that fits overthe distal end of the outer cutting blade 10. The tube 80 includes aprotruding portion 81 in which the passage of the suction passageforming member is disposed.

FIGS. 7 and 8 are views similar to FIGS. 4 and 5, but relate to thesecond embodiment using the tube 80. The protruding portion 81 includesan inlet 82, an internal suction passage 84 and an outlet 86 thatcommunicates with the suction aperture 40. The second embodimentfunctions similar to the first embodiment, and thus its method of usewill not be further described.

The tube 80 can be either permanently attached to the outer cuttingblade 10 (for example, by welding), or it can be detachably attached tothe outer cutting blade 10. For example, according to some embodiments,the tube 80 can slide onto and off of the outer cutting blade 10. Thetube 80 can be plastic or metallic, and can be made from the samematerial as the outer cutting blade 10 or from a material that differsfrom the material used to make the outer cutting blade 10.

In both embodiments, it is preferable to make the inlet of the suctionpassage forming member (for example, inlet 52 or inlet 82) tapered toease insertion of the surgical instrument into a passage of the patient.Both the first and second embodiments cause the overall diameter of thesurgical instrument 8 to be increased. Thus, tapering the inlet (forexample, 52 or 82) serves to ease insertion of the surgical instrumentinto a patient passage. Furthermore, it is preferable to make the halftube 50 and the tube 80 as small as possible to minimize the increase inthe overall diameter of the surgical instrument. For example, accordingto one embodiment, the half tube 50 has a wall thickness of about 0.015inches and a height of about 0.039 inches (i.e., a height equal toone-half of an outer diameter of 0.078 inches). However, these are justexamples, and smaller (or larger) dimensions and wall thicknesses arepossible. It is desirable that the half tube 50 or the tube 80completely cover the suction aperture 40 and that the tapered frontportion (having inlet 52/82) not allow any of the aperture 40 to be leftexposed so as to prevent the unwanted cutting of tissue.

In the illustrated embodiments, the suction aperture 40 is disposeddiametrically opposite from the cutting window 60 of the outer cuttingblade 10. However, the suction aperture need not be preciselydiametrically opposite from the cutting window 60.

When the instrument 8 is used for surgery, the surgical instrument 8 isinserted into a passage of a patient. Either before or after (or bothbefore and after) a cutting operation is performed, the surgicalinstrument 8 can be used to perform a suctioning operation. Thesuctioning operation includes positioning the inner blade 9 relative tothe outer blade 10 so that the cutting windows 30 and 60 are misalignedwith each other so that the internal bore 25 of the cutting blade 9 doesnot communicate with the passage of the patient into which the surgicalinstrument is inserted through either of the cutting windows 30 and 60.A vacuum applied through the internal bore 25 of the cutting blade 9draws material from the passage of the patient into the internal bore 25through the inlets 52/82, the internal passage 54/84, the outlet 56/86and the suction aperture 40. During performance of the suctioningoperation, the inner cutting blade 9 is not rotated relative to theouter cutting blade 10.

Thus, it is unnecessary to withdraw the surgical cutting instrument 8from the patient when switching between a cutting operation and asuctioning operation. Moreover, a separate suctioning wand may not beneeded. Thus, the surgical procedure that is performed with the surgicalinstrument 8 can be performed more quickly and while causing less traumato the patient.

In the illustrated embodiments, the inner and outer cutting blades 9 and10 are straight. However, the surgical instrument 8 can have one or morebends in it such that it is not straight. In such an arrangement, theinner cutting blade 9 would be flexible. Flexible hollow cutting bladesare known and used with curved cutting instruments. See, for example,U.S. Pat. No. 4,646,738, the disclosure of which is incorporated hereinby reference in its entirety, and see, for example, U.S. Pat. No.5,707,350, the disclosure of which is incorporated herein by referencein its entirety.

The illustrated exemplary embodiments of the surgical tool as set forthabove are intended to be illustrative and not limiting. Various changesmay be made without departing from the spirit and scope of theinvention.

1. A surgical instrument comprising: a first cutting blade having atubular body with a proximal end and a distal end, a cutting windowdisposed at a first side of the first cutting blade near the distal end,a suction aperture disposed at a second side of the first cutting bladenear the distal end; a second cutting blade having a tubular body with aproximal end and a distal end, a cutting window disposed at a side ofthe second cutting blade near the distal end, the second cutting bladerotatably disposed inside of the first cutting blade such that thesurgical instrument cuts tissue by rotating the second cutting bladewithin the first cutting blade while a vacuum is applied through aninternal bore of the second cutting blade to draw the tissue into thecutting windows of the first and second cutting blades and sever thetissue by rotation of the second cutting blade; and a suction passageforming member disposed over the suction aperture of the first cuttingblade, the suction passage forming member including an inlet, an outletand a passage between the inlet and the outlet, the outlet communicatingwith the suction aperture, the inlet facing distally, wherein thesurgical instrument can be used as a suction tool by applying the vacuumthrough the internal bore of the second cutting blade while the secondcutting blade is stopped from rotating with the cutting windows of thefirst and second cutting blades misaligned with each other so that thevacuum is applied through the suction aperture and the suction passageforming member.
 2. The surgical instrument of claim 1, wherein thesuction aperture is an elongated slot.
 3. The surgical instrument ofclaim 1, wherein the suction passage forming member is half tube that isattached to an outer surface of the first cutting blade so as to coverthe suction aperture, the half tube having a closed end and an open end,the open end defining the inlet.
 4. The surgical instrument of claim 3,wherein the half tube is metallic.
 5. The surgical instrument of claim1, wherein the suction passage forming member is a tube that fits overthe distal end of the first cutting blade, the tube having a protrudingportion in which the passage is disposed.
 6. The surgical instrument ofclaim 5, wherein the tube is metallic.
 7. The surgical instrument ofclaim 5, wherein the tube is plastic.
 8. The surgical instrument ofclaim 5, wherein the tube is slidably detachable and attachable to thefirst cutting blade.
 9. The surgical instrument of claim 1, wherein thesuction passage forming member has a distal end at which the inlet islocated, the distal end of the suction passage forming member beingtapered.
 10. The surgical instrument of claim 1, wherein the suctionpassage forming member is plastic.
 11. The surgical instrument of claim1, wherein the suction passage forming member is metallic.
 12. Thesurgical instrument of claim 1, wherein the first and second cuttingblades are made from a sterilizable material.
 13. The surgicalinstrument of claim 1, wherein the first and second cutting blades aremade from a metal.
 14. The surgical instrument of claim 13, wherein thefirst and second cutting blades are made from stainless steel.
 15. Thesurgical instrument of claim 1, wherein a passage exists between thefirst and second cutting blades through which a liquid can be supplied.16. A surgical method comprising: inserting the surgical instrument ofclaim 1 into a passage of a patient; and performing a suctioningoperation, the suctioning operation including: positioning the secondcutting blade relative to the first cutting blade so that the cuttingwindows of the first and second cutting blades are misaligned with eachother so that the internal bore of the second cutting blade does notcommunicate with the passage of the patient through either of thecutting windows of the first and second cutting blades, and applying avacuum through the internal bore of the second cutting blade to drawmaterial from the passage of the patient into the internal bore of thesecond cutting blade through the suction passage forming member and thesuction aperture.
 17. The surgical method of claim 16, wherein the firstand second cutting blades are not rotated relative to each other duringthe step of applying the vacuum.
 18. The surgical method of claim 16,further comprising: performing a cutting operation either before, after,or both before and after, performing the suctioning operation, whereinthe cutting operation includes: rotating the second cutting bladerelative to the first cutting blade while applying the vacuum throughthe internal bore of the second cutting blade.
 19. The surgical methodof claim 18, wherein the cutting operation further includes: supplyingliquid through a passage that exists between the first and secondcutting blades.